Did methane release leave behind the mysterious Siberian crater?

In mid-July, a mysterious 30-meter-wide crater was spotted in the frozen Yamal peninsula in Siberia. Although many theories abounded over the cause of the crater, researchers in Russia believe the mysterious hole was left behind when permafrost thawed and collapsed and methane released. Andrei Plekhanov, a Russian archaeologist who is studying the hole, found that the concentration of methane in the crater was unusually high, up to 9.6%. Winters in Yamal are bitter, but the summers of 2012 and 2013, which were warmer than usual by about 5°C, might have created a gas pressure leading to an outward explosion of the gas. The locals have reported sighting similar holes in the area, and scientists now worry that the release of trapped methane could threaten local industry and communities.

Read more in Nature.